1. Field of the Invention
The present invention relates to a process for producing a magnetic tape. More particularly, the present invention relates to a process for producing a magnetic tape suitable for use in backup of data for computer.
2. Description of the Related Arts
In a stage for producing a wide variety of tape for storing backup data of computer represented by cassette tape and videotape, wide raw fabric (hereinafter referred to as “web”) wound on a rewinding reel in a bulk state is supplied to a slitter via a plurality of guide rollers, and is cut into magnetic tapes by means of the slitter. Each of cut magnetic tapes is continuously transferred to a winding machine side to be wound on a hub.
Here, it is required for the cassette tape and the videotape that the size of each tape in the width direction should be within the tolerable error level of ±10 μm. On the other hand, in the case of a metal tape for storing backup data of computer, since at least one servo track is recorded on at least one side of the width direction of the tape, it is required that the size of each tape in the width direction should be within the tolerable error level of ±5 μm. Irregardless of the width, a highly precise slitter having an element precision of ±2 μm is used.
However, in spite of using such a highly precise slitter, there occurs the situation in the actual magnetic tape production line where the width size of each of magnetic tapes cut from a portion near the center of the web in the width direction sometimes becomes +8 μm, which largely exceeds the upper limit of the tolerable error level.